The present invention relates to a spindle drive with a support tube, in particular for adjusting a movable part in a motor vehicle.
Publication EP 0 759 374 A2 makes known a device for adjusting a seat in a motor vehicle, which may absorb considerably greater forces than it does during normal operation. Forces such as these are generated, e.g., during a traffic accident. It is important that the vehicle seat remain fixedly connected with the body, to ensure that the protective measures (seat belt, air bag) provided for the vehicle occupants may perform their intended function. With the device described above, a counternut that accommodates a threaded spindle is fixedly connected with the body. The threaded spindle is driven via a worm gear pair by an electric motor, which is fixedly connected with the seat. The transmission housing of the worm gear pair is made of plastic and is connected with the drive motor via a further housing part. When the drive motor is actuated, the threaded spindle rotates and displaces the transmission housing, including the drive motor and seat, relative to the counternut. To prevent the transmission housing from tearing loose from the threaded spindle, e.g., when an accident occurs, an additional, metallic, U-shaped support part is provided, which connects the transmission housing via a hinged fastening bolt with the drive motor and, therefore, the seat. The disadvantage of this design is that the U-shaped support part is unable to prevent the spindle from buckling when it is compression loaded.